DAVOS, Switzerland — In an exclusive interview on Friday, British Prime Minister David Cameron told Mic that defeating extremism is "the battle of our generation."

"For many in your audience, I think this is something people really need to understand, the scale of the threat that we face," Cameron said. "It's the battle of our time."

In a wide-ranging foreign policy conversation with Mic at the annual meeting of the World Economic Forum, Cameron sketched out his vision on a series of issues, including the fight against global terrorism, the war in Syria and the refugee crisis. Cameron said that he and President Barack Obama are working "very closely together" and are "one and the same" in their approach to defeating the Islamic State, also known as ISIL, ISIS or Daesh.

At its core, Obama and Cameron's shared approach is rooted in striking ISIS militarily in order to disrupt its stranglehold on territory in Syria and Iraq, while also confronting the ideological threat that groups like ISIS pose to Western democracy. Both state leaders have distinguished their approaches from politicians like Republican frontrunner Donald Trump by emphasizing tolerance and saying that the West is engaged in a clash of civilizations not with Islam, but with Islamic extremism.

"They are making a fundamental mistake of trying to blame all of Islam and all Muslims for what is the ideology and the actions of a minority."

That extremism, according to Cameron, is not a manifestation of Islam, but rather a "perversion of one of the world's great religions."

Cameron was clear to point out that immigrants have a set of obligations they must fulfill if they are to successfully integrate into Europe. Chief among them, according to Cameron, is learning the English language.

"I'm not asking everyone to give up their customs and practices and culture, but I think you do have to try and build something together," Cameron said. "We don't want separate development in our country."

On that point, Cameron acknowledged that the United Kingdom, along with other European countries, must do more to recreate the "melting pot model of the United States" rather than let Muslims follow their own traditions and live as separate communities inside Europe.

Read the transcript of our conversation below, condensed and edited for clarity:

Mic: In his State of the Union address, President Barack Obama said that, although San Bernardino was a tragedy, he doesn't view ISIS as an existential threat. What is your perspective when it comes to ISIS, in the wake of Paris? How do you assess the threat of Islamic extremism?

David Cameron: I think that it is the biggest threat that we face in our world at the moment, because of course, we are robust and strong democracies, we are incredible, successful economies. In the case of Britain, or the United States, we are pretty successful multiracial, multifaith democracies that can give people great opportunities.

So we're robust, but I think this perversion of one of the world's great religions by the Daesh group, and al-Qaida as well, is a major battle within Islam, and we must make sure that the right side wins it. That means fighting the terrorists in Syria. It means strengthening countries that have a particular threat from these extremists. But it also means winning this great ideological battle and pointing out that their ideology is a poisonous death cult.

I do think it's a huge threat. I think it's going to be with us for many years. I often describe it as the battle of our generation. For many in your audience, I think this is something people really need to understand, the scale of the threat that we face.

When you look at root causes, and your strategy in Syria moving forward, how do you take on this threat? Specifically, what's your case for a combination of military action, plus addressing the ideological piece?

DC: I think it's important to be clear about the root causes, because some people want to try and blame poverty, or try to blame Western foreign policy, or try and seek some other answer to this, other than the one that I think is staring us in the face, which is: This is a perverted ideology, and we'll only confront and defeat it if we deal with the ideology, and if we win the battle, which is that Islam is a religion of peace and that this is a perversion of Islam. That's why the ideological fight is so important.

The military action is important in Syria and Iraq because, effectively, these extremists have set up a quasi-state, and that state has land, it has money, it has weapons, and so it's able not only to make life miserable for people in Iraq and Syria who want a decent government that represents them and their families, but it also is a base from which they can carry out attacks on the rest of the world.

We saw that most clearly with the attack in Paris, which came directly from [rancor] in Syria.

I was recently in Lesbos, and spent some time with refugees. You've spoken a lot about the challenges around integration. Moving forward, with Syria in its current state, and refugees continuing to come into Europe, how do you address the integration challenge?

DC: Clear thinking is needed on these issues. The first thing to remember is the choice of most refugees. Choice number one would be to go back to Syria.

Choice number two for people is actually to stay in the region and be able to work in the region, and that's why we spend on aid. Britain is second only to the United States in aid. We've spent around $1.5 billion supporting these refugees, and we're now trying to help people work in the region, working with their countries.

Choice number three is coming to Europe. So we need to make sure we're responding to choice number two and choice number one as much as we can.

Britain, like America, is a very successful multiracial, multifaith democracy. We have integrated people into our country in the past and will do so again. For instance, we're going to take 20,000 Syrian refugees directly out of the camps. I think the challenge for countries in Europe is to find a way of integrating people so they feel part of a society and country that you're building together.

British Prime Minister David Cameron meets pupils at the Safiyyeh Bint Abdel Muttaleb Girls School in the town of Zaatari, which receives funding from the UK government on September 14, 2015 in Amman, Jordan. Pool/Getty Images

Crucial to that is making sure that new arrivals learn the language, learn English. Then it's about making sure they can have all the opportunities of living in a great democratic and tolerant country.

But we need to be clear about not just our obligations to those who come, but the obligations of those people who arrive. The obligation, for instance, to learn the language. I'm not asking everyone to give up their customs and practices and culture, but I think you do have to try and build something together. We don't want separate development in our country.

I think sometimes in the past, Britain and some other European countries almost said to people as they were coming, "You can live a separate life in our country," rather than the melting pot model of the United States that I think has been more successful.

Have there been any differences of opinion between you and President Obama when it comes to dealing with the refugee crisis or the Syria strategy?

DC: No, I think we are very closely aligned. We work extremely well together and have done so for the last five years. Britain and America are absolutely at the heart of the global coalition taking on Daesh in Syria and Iraq. Our military strategies are absolutely one and the same. We work very closely together on that. We both see the scale of the threat, and we want to address it in all of the ways we've discussed.

Obviously, as partners, we have our discussions and arguments about how best to do these things. But they are discussions between friends and partners who have worked together on so many vital conflicts, whether it has been on the beaches of D-Day, fighting global threats in the Cold War and the battle against communism, or the battle that I think our generation faces today against Islamist extremism, which we have to be as united and as resolute in defeating.

Donald Trump has spoken out about these issues. There's been a lot of talk in the UK about banning him from entering the country. What are your comments on his rhetoric around these issues?

DC: I think the problem with what Donald Trump has said, and what some others say too, is they are making a fundamental mistake of trying to blame all of Islam and all Muslims for what is the ideology and the actions of a minority, and I think that's wrong. In many ways, it actually helps the extremists, because they want to create a clash of civilizations between Islam and Christianity, or Islam and the West.

Actually, what's happening is not a clash of civilizations. It is a fight within Islam, where the overwhelming majority rightly see Islam as a religion of peace, and want to live in successful multiracial, multi-ethnic, multifaith democracies like ours, and make an incredible contribution to our country, as opposed to a small minority that believe this rhetoric of poisonous extremism, and many of this tiny minority then believing in violence.

So, what Donald Trump says is, in my view, not only wrong, but actually it makes the work we need to do to confront and defeat the extremists more difficult.